Venture capitalists and fashion startups don’t always see each other eye-to-eye.

First, there’s the gender gap: fashion founders often have to defend their businesses to VC partners, 92 percent of which are men who don’t spend a lot of time shopping online. There’s also the high risk, low reward reputation of the retail industry: it’s a category dominated by established players like Amazon that doesn’t see the same return as fast-growing industries like software and healthcare.

Investors, however, are placing big bets on one fashion-tech sector: the online resale marketplace.

Between 2009 and 2012, the online consignment business swelled as sites like Vestiaire Collective, ThredUp, The RealReal, ThreadFlip, Poshmark, Tradesy, Twice and Vaunte popped up to bring the ancient art of secondhand shopping to a digital marketplace. Since that initial boom, weaker competitors have folded into other companies or shuttered, while leading players have become increasingly flush with cash.

According to data from fashion investment community FashInvest, investors funneled more than $175 million into the online reselling industry in 2016. The question of when the inevitable bubble will burst has been raised, but it hasn’t happened yet: Vestiaire Collective, a Paris-based online reselling platform for luxury goods, secured a $62 million round of funding this week led by venture firm Vitruvian Partners.

With its latest injection of cash — the company has now raised a total of $130 million in five rounds of funding — the luxury consignment marketplace has its sights set on international expansion, particularly in the U.S. and Asia. Top competitors have closed similarly hefty investment rounnds: The RealReal has raised a total of $122 million, while ThredUp has raised $131 million.

“What’s appealing to investors is that these companies don’t rely on inventory, and they’re community driven,” said Ashley Paintsil, FashInvest’s editorial director. “Buying secondhand is trendy right now, and investors chase what’s going on at the moment. They go where the money is, and right now, they’re putting their money there.”

Unlike previous hot-button fashion tech trends that have come to pass, like flash-sale sites and subscription models, consignment is not new to consumers. For investors, the marketplace makes sense: it’s steadily aligned consumer behavior, as shoppers aren’t going to simply stop buying Birkin bags or vintage Chanel.

What online companies in the space have to figure out is how to have the most diverse inventory, the most committed community and, for luxury sites, speedy, trustworthy authentication practices.

Competition among marketplaces is also closing in on the international title.

“Having an international catalog and community is what gives us our edge,” said Samina Virk, the head of U.S. for Vestiaire Collective. “We want to connect the closets of women all over the world — right now, American women don’t really have access to that on U.S. sites. That’s a strong differentiator.”

Virk sees getting on the ground in new markets as key to growth, as ultimately, online luxury consignment competitors are working with the same finite pool of inventory.

“Any retail or e-commerce model is dependent on supply,” she said. “A lot of the resellers in the U.S. are fighting over the same supply and customers, since the supply is in people’s closets. We’re not dependent on buying inventory, just getting people on board to expose it.”

According to Cheryl Cheng, a partner at investment firm BlueRun Ventures, competition among online consignment companies will eventually drill down to who can get their clutches on the most valuable customers.

“The real differentiation is not around the technology,” said Cheng. “It’s not about whether a website is faster, or a mobile site is that much more amazing. It’s about getting the most inventory you can get your hands on that people will desire. It’s a merchandising game, not unlike Barneys’ or Neiman’s.”

While companies duke it out to have the best online experience and most valuable inventory, investors are continuing to be bullish on the space’s potential growth.

“There isn’t really a risk here,” said Paintsil. “People have been secondhand shopping since the beginning of time, and right now, it’s more interesting to say you found something online from an old Gucci collection rather than you picked something up from Zara. It will continue to grow, and we’ll see about four to five major players emerge in different markets.”

Cheng said that, down the line, she could foresee global consolidation — one dominant eBay-like marketplace for online luxury consignment. (Since they’re not dealing with much resale value, companies like ThredUp, which focus on down-market apparel, will likely fade away.)

“If a new U.S. company were to come into my office today and was doing The RealReal again, I would say, ‘Good luck.’ In each large market, you’re only going to have one winner,” she said. “International, though, is different. The luxury market has always been global, but U.S. companies don’t always understand Asia, and vice-versa. There’s room for global.”